Recent Progress in Nucleic Acid Aptamer-Based Biosensors and Bioassays

Abstract

As the key constituents of the genetic code, the importance of nucleic acids to life has long been appreciated. Despite being composed of only four structurally similar nucleotides, single-stranded nucleic acids, as in single-stranded DNAs and RNAs, can fold into distinct three-dimensional shapes due to specific intramolecular interactions and carry out functions beyond serving as templates for protein synthesis. These functional nucleic acids (FNAs) can catalyze chemical reactions, regulate gene expression, and recognize target molecules. Aptamers, whose name is derived from the Latin word aptus meaning “to fit”, are oligonucleotides that can bind their target ligands with high affinity and specificity. Since aptamers exist in nature but can also be artificially isolated from pools of random nucleic acids through a process called in vitro selection, they can potentially bind a diverse array of compounds. In this review, we will discuss the research that is being done to develop aptamers against various biomolecules, the progress in engineering biosensors by coupling aptamers to signal transducers, and the prospect of employing these sensors for a range of chemical and biological applications. Advances in aptamer technology emphasizes that nucleic acids are not only the fundamental molecules of life, they can also serve as research tools to enhance our understanding of life. The possibility of using aptamer-based tools in drug discovery and the identification of infectious agents can ultimately augment our quality of life.

Flow Cytometry-Assisted Detection of Adenosine in Serum with an Immobilized Aptamer Sensor

“…3 While protein enzymes and antibodies are the traditional molecules of choice for making biosensors, aptamers are emerging as a promising alternative due to their small sizes, high stability (especially DNA aptamers), ease of modification and immobilization, and excellent target recognition properties. [4][5][6][7][8][9][10][11][12][13][14][15][16] Aptamers are single-stranded nucleic acids that can selectively bind to target molecules. [17][18][19] Because of their useful properties, aptamers have been widely used for constructing biosensors.…”

A label-free DNA aptamer-based impedance biosensor for the detection of E. coli outer membrane proteins

“…Aptamers can be generated by a combinatorial procedure called "systematic evolution of ligands by exponential enrichment" (SELEX) [9] and synthesized in a large quantity in vitro in a very reproducible way [10,11]. Several aptamers have been developed to bind different targets, like proteins, small molecules, cells, antibiotics, and viruses [10], in various types of biodetection approaches from label-free [12] to self-reporting or labeling strategies [13] using a variety of assay formats [14].…”

Recent progress in the construction methodology of fluorescent biosensors based on biomolecules

“…Thus, the design of aptamer-based fluorescent sensors represents an attractive and promising alternative to the protein-based sensors. Some excellent reviews of aptamer sensors have already covered the selection and evolution techniques and sophisticated applications of the aptamer sensors Mok, W. et al 2008]. Here we focus on unique modular strategies to construct aptamer sensors, which would avoid the cumbersome trial-and-error process to construct a sensor with an optimized function.…”